MX391, MX392, and MX393 Microflex Wired Boundary Microphones from Shure are the smartest boundary microphones yet.  Equipped with features like programmable, silent membrane switches, logic inputs and outputs, and LED indicators, Microflex Boundary microphones are the high-quality solution for a range of applications, such as altars, boardrooms and distance learning centers. Every Microflex Boundary microphone features a choice of interchangeable condenser cartridges. 

Available in cardioid, supercardioid and omnidirectional polar patterns, the Microflex cartridges give you superior Shure quality sound for every application. In addition, their programmable switches offer the flexibility to be set for Push to Talk, Push to Mute or Push On/Push Off modes. Attractively designed with a low profile, professional appearance, the Microflex Boundary microphones come with an easy to use paint mask for your custom-color installations. Find out why we call the Microflex Boundary microphones "the smart choice" for just about every application. Take a listen today.

The polar pattern of the cartridge is indicated by the model number suffix:

C = Cardioid, S = Supercardioid, O= Omnidirectional 

MX392/C  All measurements taken with microphone mounted on a wooden surface 76.2 cm x 76.2 cm (30 in. x 30 in.).   Frequency Response 50 to 17,000 Hz Polar Pattern Cardioid (MX392/C, MX393/C) Supercardioid (MX392/S, MX393/S) Omnidirectional (MX392/O, MX393/O) Output Impedance EIA Rated at 150 ohms (180 ohms actual) Sensitivity (at 1 kHz, open circuit voltage) Cardioid Cartridge: -27.5 dBV/Pa (42.2 mV) Supercardioid Cartridge: -26.5 dBV/Pa (47.3 mV) Omnidirectional: -22.0 dBV/Pa (79.4 mV) 1 Pascal=94 dB SPL Maximum Sound Pressure Level (1 kHz at 1% Total Harmonic Distortion, 1 k ohm load) Cardioid: 117.0 dB Supercardioid: 116.0 dB Omnidirectional: 111.5 dB Signal to Noise Ratio (referenced at 94 dB SPL) Cardioid: 71.0 dB Supercardioid: 72.0 dB Omnidirectional: 76.5 dB Equivalent Output Noise (A-weighted) Cardioid: 23.0 dB Supercardioid: 22.0 dB Omnidirectional: 17.5 dB Dynamic Range 94.0 dB Common Mode Rejection 45 dB minimum, 10 Hz to 100 kHz Switch Attenuation 50 dB minimum Preamplifier Output Clipping Level -6 dBV (0.5 V) Polarity Positive sound pressure on diaphragm produces positive voltage on pin 2 relative to pin 3 of output connector. Logic Connections (MX392 Only) LED IN: Active low (<1.0v), TTL compatible. Absolute maximum voltage: -0.7V to 50V. SWITCH OUT: Active low (<0.5V), sinks up to 20mA, TTL compatible. Absolute maximum voltage: -0.7V to 24V (up to 50V through 3 k ohms). Power Requirements 11 to 52 Vdc phantom 2.0 mA current consumption Environmental Requirements Operating Temperature Range: -18 to 57 degrees C (0 to 135 degrees F) Relative Humidity: 0 to 95% Dimensions See User Guide R W Salt Communications Limited, Unit 12 Wheel Forge Way, Ashburton Park, Trafford Park, Manchester. M17 1EH TEL: 0844 980 8800 FAX: 0844 980 8802 Email: sales@rwsalt.co.uk Company Reg No: 2355159